Demonstration drop test and design enhancement of the CANDU spent fuel storage basket in dry storage facility

▶ Demonstration drop test for a CANDU spent fuel storage basket in dry storage facility was performed. ▶ Leakage happened in the upper welding region of a loaded basket after drop test. ▶ Design revision based on the results of FE analyses and specimen tests was conducted. ▶ Revised basket satisfied all the requirements in additional demonstration test. A dry interim storage facility has been constructed at the Wolsung power plant in Korea. This dry storage facility has seven separated modules. There are 40 long slender cylinders in one module. In one cylinder, ten baskets where sixty CANDU spent fuel bundles are loaded are stacked and stored. For this dry storage facility, analyses and tests for hypothetical accident conditions that might occur while moving and storing the baskets into a cylinder were performed. In a demonstration test, one of test basket models did not satisfy one of the safety-related requirements. Thus, the revised basket designs were generated using a structural evaluation based on finite element analyses and specimen tests. Among these revised designs, one design was chosen as a final revised basket design. The final revised design was the one creating the largest reduction of plastic strain in the upper welding region. It was also the one that required the smallest design change from the current basket design for easy adoption. Drop and leak tests were performed, and the final revised basket satisfied all performance requirements.